Assessment of the current and emerging criteria for the histopathological classification of lung neuroendocrine tumours in the lungNENomics project.

BACKGROUND: Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort presents a unique opportunity to assess the strengths and limitations of current World Health Organization (WHO) classification criteria and to evaluate the utility of emerging markers. PATIENTS AND METHODS: Patients were diagnosed based on the 2021 WHO criteria, with atypical carcinoids (ACs) defined by the presence of focal necrosis and/or 2-10 mitoses per 2 mm2. We investigated two markers of tumour proliferation: the Ki-67 index and phospho-histone H3 (PHH3) protein expression, quantified by pathologists and automatically via deep learning. Additionally, an unsupervised deep learning algorithm was trained to uncover previously unnoticed morphological features with diagnostic value. RESULTS: The accuracy in distinguishing typical from ACs is hampered by interobserver variability in mitotic counting and the limitations of morphological criteria in identifying aggressive cases. Our study reveals that different Ki-67 cut-offs can categorise LNETs similarly to current WHO criteria. Counting mitoses in PHH3+ areas does not improve diagnosis, while providing a similar prognostic value to the current criteria. With the advantage of being time efficient, automated assessment of these markers leads to similar conclusions. Lastly, state-of-the-art deep learning modelling does not uncover undisclosed morphological features with diagnostic value. CONCLUSIONS: This study suggests that the mitotic criteria can be complemented by manual or automated assessment of Ki-67 or PHH3 protein expression, but these markers do not significantly improve the prognostic value of the current classification, as the AC group remains highly unspecific for aggressive cases. Therefore, we may have exhausted the potential of morphological features in classifying and prognosticating LNETs. Our study suggests that it might be time to shift the research focus towards investigating molecular markers that could contribute to a more clinically relevant morpho-molecular classification.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids.

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

[Interstitial processes of the lungs in childhood]. / Interstitielle Prozesse der Lunge im Kindesalter.

Interstitial processes in the lungs of children can be due to several underlying diseases. Knowledge of the child's age is important as genetic aberrations play a major role in diseases in the first 2 years, whereas immunological diseases are more common starting in kindergarden age. In general lung diseases are rare in children, which makes the diagnostics difficult and results in a delayed diagnosis. In addition, pediatric pulmonologists are often very reluctant to perform lung biopsies due to a lack of a specialized pathologist. In order to make a contribution to the diagnostics of pediatric pulmonary diseases, pathologists should be specialized in pulmonary pathology, have a good knowledge of genetic methods and fetal lung development, which includes the genetic factors involved in lung growth and differentiation. A close cooperation with the pediatric pulmonologist is necessary and each patient should be discussed jointly on an interstitial lung disease board to promote the quality of diagnostics. The pathologist should be aware that the developing lungs of children are not just a smaller form of adult lungs and often react very differently. In this article, we mainly focus on diffuse infiltration patterns, such as ground glass and reticulonodular infiltrations as described in high-resolution computed tomography (HRCT). Localized interstitial processes, which can sometimes be tumor-like and malformations are not dealt with; however, vascular malformations are included as these often manifest as diffuse interstitial infiltrations and must therefore be taken into consideration for the differential diagnostics.

[Neuroendocrine neoplasms of the mediastinum]. / Neuroendokrine Neoplasien des Mediastinums.

Primary neuroendocrine tumors (NET) in the mediastinum are very rare and among them thymic NETs are the most common. They represent 5 % of all thymic and mediastinal tumors. The WHO classification from 2015 subdivides thymic NETs into three groups; low grade (typical carcinoid), intermediate grade (atypical carcinoid) and high grade (large cell neuroendocrine carcinoma and small cell carcinoma). Through this change of mediastinal/thymic NET classification into three groups of malignancy, the nomenclature was adapted to that of the lungs, while the histological criteria for each entity remained the same. Thymic NETs typically occur in middle-aged adults and predominantly in males. Approximately 30 % are asymptomatic and the rest present with symptoms caused by local tumor growth, distant metastases and/or endocrine manifestations. Carcinoids can also occur as a part of multiple endocrine neoplasia type 1 (MEN1) and at the time of diagnosis commonly present with regional lymph node or distant metastases, which most often affect the lungs and bones. For the correct diagnosis tumor cell morphology, mitotic count and/or necrosis are crucial. Patients with typical carcinoids have the best prognosis, whereas the prognosis is slightly worse for atypical carcinoids but very poor for large cell neuroendocrine carcinomas. Small cell carcinomas have the worst prognosis and the shortest median survival time of approximately 14 months.

[Pulmonary Langerhans cell histiocytosis]. / Die pulmonale Langerhans-Zell-Histiozytose.

Pulmonary Langerhans cell histiocytosis is regarded as a reactive proliferation of the dendritic Langerhans cell population stimulated by chronic tobacco-derived plant proteins due to incomplete combustion but can also occur in childhood as a tumor-like systemic disease. Currently, both these forms cannot be morphologically distinguished. In the lungs a nodular proliferation of Langerhans cells occurs in the bronchial mucosa and also peripherally in the alveolar septa with an accompanying infiltration by eosinophilic granulocytes and destruction of the bronchial wall. Langerhans cells can be selectively detected with antibodies against CD1a and langerin. In the reactive isolated pulmonary form, abstinence from tobacco smoking in most patients leads to regression of infiltration and improvement of symptoms. In high-resolution computed tomography (HRCT) the small star-like scars can still be detected even after complete cessation of tobacco smoking.

Overcoming resistance to first generation EGFR TKIs with cetuximab in combination with chemotherapy in an EGFR mutated advanced stage NSCLC patient.

We report the case of a female never-smoking patient with an epidermal growth factor receptor (EGFR) mutation positive advanced non-small cell lung cancer (NSCLC) who received multiple lines of treatment. When she evolved clinical resistance to first generation EGFR tyrosine kinase inhibitors (TKI), she was treated with a fifth-line combination therapy with cetuximab and vinorelbine. This combination was highly active with a treatment response lasting for 9 months supporting the hypothesis that EGFR monoclonal antibodies in combination with chemotherapy may play a role in reversing EGFR-TKI resistance in EGFR mutation-positive NSCLC.

EGFR and PDGFR differentially promote growth in malignant epithelioid mesothelioma of short and long term survivors.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an asbestos related tumour difficult to detect early and treat effectively. Asbestos causes genetic modifications and cell signalling events that favour the resistance of MPM to apoptosis and chemotherapy. Only a small number of patients, approximately 10%, survive more than 3 years. The aim of our study was to assess possible differences within signalling pathways between short term survivors (survival <3 years; STS) and long term survivors (survival >3 years; LTS) of MPM. METHODS: 37 antibodies detecting proteins engaged in cell signalling pathways, enforcing proliferation, antiapoptosis, angiogenesis and other cellular activities were investigated by tissue microarray (TMA) technology. RESULTS: Epidermal growth factor receptor (EGFR) was expressed stronger in LTS whereas platelet derived growth factor receptor (PDGFR) signalling was more abundant in STS. Expression of TIE2/Tek, a receptor for tyrosine kinases involved in angiogenesis, was differentially regulated via PDGFR and thus is more important in STS. Antiapoptosis was upregulated in STS by signal transducer and activator of transcription 1 (STAT1)-survivin and related molecules, but not in LTS. Our study provides novel insights into the regulatory mechanisms of signalling pathways in MPM, which differentially promote tumour growth in LTS and STS. CONCLUSION: We have demonstrated that small scale proteomics can be carried out by powerful linkage of TMA, immunohistochemistry and statistical methods to identify proteins which might be relevant targets for therapeutic intervention.

Early-life pulmonary arterial hypertension with subsequent development of diffuse pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia type 1.

The case history is presented of a male infant who was thought to have idiopathic pulmonary arterial hypertension (PAH) at 3 months of age. Subsequently the PAH decreased unexpectedly and diffuse pulmonary arteriovenous malformations (PAVMs) were seen at 6.9 years of age for the first time. Hereditary haemorrhagic telangiectasia type 1 (HHT1) related to an endoglin mutation was diagnosed. At 10.3 years of age a lung biopsy showed diffuse PAVMs as well as pulmonary arteriopathy with medial hypertrophy. This is the first case of HHT1 presenting with PAH at such a young age. The subsequent decrease in pulmonary arterial pressure (PAP) was probably caused by the development of PAVMs. In the presence of PAVMs, measurement of the PAP may underestimate the extent of PAH-related vasculopathy.

Expression of CCX CKR in pulmonary sarcoidosis.

OBJECTIVE: CCX CKR is a decoy chemokine receptor that specifically binds the chemokines CCL19, CCL25 and CCL21. CCL19 was previously found to be upregulated in pulmonary sarcoidosis. We have, therefore, investigated CCX CKR expression in this inflammatory disease. METHODS AND RESULTS: CCX CKR mRNA was semiquantitated using RT-PCR in unseparated bronchoalveolar (BAL) cells from sarcoidosis patients (S, n = 29) and healthy control subjects (C, n = 9). CCX CKR transcripts were upregulated in patients (mean +/- SEM); S, 0.82 +/- 0.10; C, 0.44 +/- 0.04; p = 0.01; this upregulation paralleled the disease course as assessed by the chest radiographic stage (p < 0.02). Immunocytochemistry localised the CCX CKR protein to ciliated bronchial cells. Flow cytometric fluorescent ligand uptake assay showed that these cells are able to internalize its ligand. CONCLUSION: These observations implicate CCX CKR in the modulation of the inflammatory response in sarcoidosis.

Pulmonary infiltrates in patients with haematologic malignancies: transbronchial lung biopsy increases the diagnostic yield with respect to neoplastic infiltrates and toxic pneumonitis.

We retrospectively evaluated 107 fiberoptic bronchoscopies with and without transbronchial lung biopsy (TBLB) in 98 consecutive patients with haematologic malignancies and pulmonary infiltrates. Bronchoalveolar lavage (BAL) was performed in 45 and BAL plus TBLB in 62 procedures. There was no procedure-related severe haemorrhage, pneumothorax or death. Infectious aetiology was identified in 26 of 107 (24%), toxic pneumonitis in 17 of 107 (16%) and neoplastic infiltration in 9 of 107 (8.5%) episodes. Combined BAL and TBLB was significantly superior to BAL alone with respect to the diagnosis of neoplastic infiltrates (p=0.008) and toxic pneumonitis (p<0.001) and should therefore be included in the diagnostic work-up of this patient cohort.

Invasion of blood vessels as significant prognostic factor in radically resected T1-3N0M0 non-small-cell lung cancer.

OBJECTIVES: Radical resection is the therapy of choice in non-small-cell lung cancer (NSCLC). However, even in early stages (T1N0, T2N0) up to 35% of patients will experience recurrence. The aim of this retrospective study was to evaluate the prognostic influence of lymph vessel or blood vessel invasion in N0 patients. METHODS: A total of 72 patients (male, 49; female, 23; median age 59; range 40-72) with NSCLC entered the study. The stages were T1-3N0 (T1, 25; T2, 41; T3, 6). Thirteen pneumonectomies and 59 lobectomies or bilobectomies with systematic lymphadenectomy and R0 resection were performed. Histologically, 24 adenocarcinomas, 31 squamous cell carcinomas and 14 subtypes of large cell carcinoma were found. In 22 cases microscopic invasion of the lymphatic vessels and in 11 invasions of blood vessels were found. Six patients showed invasion of either structure. RESULTS: The patients were followed up for at least 5 years or until death. During the follow-up period 27 patients died (21 because of recurrence and 6 because of diagnosis not related to NSCLC). The 5 years overall survival amounted to 62.5%. In cases with invasion of the blood vessels the survival rate was 23.5%, in cases without invasion 74.5% (P< or = 0.01), whereas lymph vessel invasion had no significant impact on survival. Multivariate analysis covering T stages, histological subtypes, location of the tumor, grading, age, sex, and invasion of the lymphatic or the blood vessels showed invasion of the blood vessels as the only factor with significant prognostic impact in the study population. CONCLUSIONS: In resectable N0 patients with NSCLC the microscopic invasion of blood vessels should be considered as an additional prognostic parameter.

Necrotizing sarcoid granulomatosis--is it different from nodular sarcoidosis?

BACKGROUND: Necrotizing sarcoid granulomatosis (NSG) was initially defined as a granulomatosis with features in between sarcoidosis and Wegener's granulomatosis (WG), but without extrapulmonary involvement. Subsequent reports have shown that extrapulmonary involvement does exist, and some have suggested NSG as a variant of sarcoidosis. MATERIAL AND METHODS: We studied 10 cases from 3 institutions, and compared clinical and histologic features with those of nodular sarcoidosis and WG. We have analyzed the 10 cases for mycobacterial chaperonin and for the insertion sequence 6110 by PCR. RESULTS AND CONCLUSIONS: Nodular aggregates of granulomas in NSG were similar to those seen in nodular sarcoidosis. Granulocytic vasculitis, a hallmark of WG was not seen in any of the NSG cases. Granulomatous vasculitis was a common feature in cases of NSG, and did not differ from that seen in sarcoidosis. The only unique feature of NSG is infarct-like necrosis, induced by the vasculitis, which might also be interpreted as a function of the duration of the vasculitis, leading ultimately to vascular obstruction. NSG based on our morphologic findings is best classified as a variant of nodular sarcoidosis. In contrast to our findings in sarcoidosis mycobacterial DNA was not found in any of the 10 cases.

A case of lung transplantation following Mycoplasma pneumoniae infection.

Reported here is a case of severe necrotizing pneumonia following Mycoplasma pneumoniae infection that occurred in a 55-year-old man. The histological changes of lung parenchyma included granulomas and bronchiolitis obliterans. Mycoplasma infection was diagnosed by repeated antibody determination (complement fixation test) and confirmed using the polymerase chain reaction to detect the pathogen from a tracheal aspirate. Prior to this episode of pneumonia, the patient had been healthy, except for Reiter's disease that had been diagnosed 18 years previously. In addition to severe pulmonary involvement, the patient developed rhabdomyolysis with subsequent acute renal failure, Stevens-Johnson syndrome, biochemical pancreatitis, severe anemia, and an effusion of the right knee. Contrary to the symptoms of pulmonary disease, all of the extrapulmonary manifestations except anemia were transient. Due to persistent respiratory insufficiency and long-term failure to wean the patient from a respirator, a lung transplantation was performed. Five weeks after transplantation the patient died as a result of intrapulmonary hemorrhage. To the best of our knowledge, this is the first report of pneumonia due to Mycoplasma pneumoniae leading to lung transplantation. Furthermore, the multiple extrapulmonary manifestations in this case make it exceptional.

Bronchiolitis obliterans. Organizing pneumonia.

Bronchiolitis obliterans combined organizing pneumonia (BOOP), now called organizing pneumonia, is a multi-etiologic disease. It can present as a solitary lesion, or as multinodular or diffuse interstitial lung disease. It is speculated if solitary BOOP may evolve into inflammatory pseudotumor of the lung. BOOP can be seen after non-resolving infectious bronchopneumonia as well as acute interstitial pneumonia with diffuse alveolar damage. BOOP can be the early morphologic pattern in toxic inhalation, especially water-soluble substances, but also in drug induced lung disease. BOOP can be the late stage of extrinsic allergic alveolitis, but also a morphologic sequel of collagen vascular disease. Even Wegener's granulomatosis can be preceded by a BOOP pattern. In many cases a careful analysis of BOOP, including changes of the pneumocytes, macrophages, myofibroblasts and endothelial cells, can establish the correct etiologic diagnosis. For example virus-induced pneumocyte proliferation can be seen months after the onset of interstitial pneumonia, and can be found within BOOP. A small percentage of BOOP, however, has to be labeled as idiopathic, which is important too, because of different modalities of therapy. Idiopathic BOOP also is different with respect to prognosis. In the overview different BOOP etiologies will be discussed, and the etiologic background will be analyzed. The pathogenesis will be discussed with respect to the understanding of the causing mechanisms. The role of bronchoalveolar lavage and the optimal tissue sample for establishing the diagnosis will be discussed and demonstrated by examples. A part of the presentation will deal with the differential diagnosis, such as usual interstitial pneumonia, non-specific interstitial pneumonia, constrictive, and respiratory bronchiolitis combined interstitial lung disease.

Sulfasalazine-induced extrinsic allergic alveolitis in a patient with psoriatic arthritis.

We report the first case of a well defined extrinsic allergic alveolitis as a complication of sulfasalazine therapy in a patient treated for psoriatic arthritis. CT of the chest showed small nodular densities over both lungs, BAL demonstrated a highly active lymphocytic alveolitis and transbronchial biopsies revealed lymphoplasmocytic interstitial infiltration. Sulfasalazine as causative agent was proven by an inadvertent rechallenge three years later and a positive lymphocyte transformation test. sulfasalazine; psoriatic arthritis; extrinsic allergic alveolitis

Chromosomal aberrations in a series of large-cell neuroendocrine carcinomas: unexpected divergence from small-cell carcinoma of the lung.

Large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) are high-grade neuroendocrine tumors of the lung. Despite different morphologic appearances, loss of heterozygosity and oncogene studies on LCNEC to date suggest genetic similarities. We analyzed 13 LCNEC and 5 mixed SCLC/LCNEC tumors by comparative genomic hybridization and subsequently compared our results with previously published data on 32 SCLCs. Comparison with SCLC showed several shared chromosomal aberrations, specifically losses of 3p, 4q, 5q, and 13q and gains of 5p. However, these aberrations are no special feature of neuroendocrine lung tumors but can also be found in other high-grade lung carcinomas. From this point of view, genetic similarities of LCNEC and SCLC are less important than the nonrandom changes that differ between these 2 tumor types. A gain of 3q observed in 66% of all SCLCs was detected only once in the LCNEC group. In contrast to the pure LCNEC, all mixed types with a SCLC component had a gain of 3q. Gains of 6p occurred more frequently in LCNEC. Deletions of 10q, 16q, and 17p were less frequent in LCNEC than in SCLC.

Relationship between Epstein-Barr virus and lymphoepithelioma-like carcinoma of the lung: a clinicopathologic study of 6 cases and review of the literature.

Lymphoepithelioma-like carcinoma (LELC) is a rare form of lung cancer, usually encountered in Chinese patients. Similar to nasopharyngeal carcinoma, LELC of the lung is strongly associated with Epstein-Barr virus (EBV) infection in Asian patients, but there is controversy over whether an association exists in patients from Western countries. To determine whether such a relationship exists, we retrospectively studied 6 cases of primary LELC of the lung, all of which were in Western patients. There were 4 men and 2 women, ranging in age from 49 to 75 years. The tumors ranged from 1 to 4.5 cm in diameter. Four patients had stage I disease, 1 had stage IIb disease, and 1 had stage IIIa disease. All patients are alive without evidence of disease with a follow-up of 18 to 30 months. Formalin-fixed, paraffin-embedded tissue was stained with hematoxylin-eosin for routine evaluation and immunostained for keratin and leukocyte common antigen (LCA). LCA staining was performed to exclude large-cell lymphoma. Immunoperoxidase staining (1:500 clone CS1-4; Dako, Carpinteria, CA) and in situ hybridization were performed to detect EBV. Tumors consisted of solid nests of undifferentiated tumor cells in a syncytial arrangement surrounded by heavy lymphoplasmacytic infiltrate. Tumor cells stained positively for keratin but negative for LCA. All 6 cases were negative for EBV, suggesting no association between EBV and LELC in the Western population.

Clinical and histopathological findings in two Turkish children with follicular bronchiolitis.

UNLABELLED: We report on two Turkish children who presented with progressive airway obstruction. Open lung biopsy revealed follicular bronchiolitis. The children were treated with systemic steroids and various topical medications. Whereas the respiratory situation of patient 1 required immunosuppressive therapy, the condition of patient 2 stabilised without systemic medication. CONCLUSION: Diagnosis of follicular bronchiolitis should be considered when children present with recurrent respiratory tract infections, progressive dyspnoea, and chronic bronchial obstruction. Children in whom follicular bronchiolitis is suspected should undergo open lung biopsy for confirmation of diagnosis.